<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Nav 导航</title>
    <link rel="stylesheet" href="index.css">
</head>
<body>
<section class="main">
    <nav>
        <ul class="clearfix">
            <li>导航栏1</li>
            <li>导航栏2</li>
            <li>导航栏3</li>
            <li>导航栏4</li>
        </ul>
    </nav>
</section>
</body>
</html>